ras_agent/application/
run_agent.rs

1use std::sync::Arc;
2
3use ras_errors::AppError;
4use ras_llm::{ChatMessage, LlmClient};
5use ras_types::{AgentId, StepId};
6
7use crate::application::run_step::RunStep;
8use crate::domain::agent_history::{AgentHistory, AgentHistoryList, StepRecord};
9use crate::domain::loop_detector::ActionLoopDetector;
10
11pub struct RunAgent {
12    pub agent: AgentId,
13    pub task: String,
14    pub max_steps: u32,
15    pub primary_llm: Arc<dyn LlmClient>,
16    pub fallback_llm: Option<Arc<dyn LlmClient>>,
17}
18
19impl RunAgent {
20    pub fn new(task: impl Into<String>, llm: Arc<dyn LlmClient>) -> Self {
21        Self {
22            agent: AgentId::new(),
23            task: task.into(),
24            max_steps: 25,
25            primary_llm: llm,
26            fallback_llm: None,
27        }
28    }
29
30    #[must_use]
31    pub fn with_fallback(mut self, fallback: Arc<dyn LlmClient>) -> Self {
32        self.fallback_llm = Some(fallback);
33        self
34    }
35
36    #[must_use]
37    pub fn with_max_steps(mut self, max_steps: u32) -> Self {
38        self.max_steps = max_steps;
39        self
40    }
41
42    pub async fn execute(self) -> Result<AgentHistoryList, AppError> {
43        let runner = RunStep::new(self.primary_llm.clone(), self.fallback_llm.clone());
44        let mut detector = ActionLoopDetector::new();
45        let mut history = AgentHistory {
46            agent: self.agent,
47            task: self.task.clone(),
48            steps: Vec::new(),
49        };
50        let mut last_step_ms: Option<u64> = None;
51        for n in 0..self.max_steps {
52            let prompt = build_prompt(&self.task, &history.steps);
53            let mut record = runner
54                .execute(StepId(n), self.max_steps, prompt, &mut detector)
55                .await?;
56            record.metadata.step_interval_ms = last_step_ms;
57            last_step_ms = Some(record.metadata.duration_ms);
58            let done = record.results.iter().any(|r| r.is_done) || record.output.action.is_empty();
59            history.steps.push(record);
60            if done {
61                break;
62            }
63        }
64        let mut list = AgentHistoryList::default();
65        list.push(history);
66        Ok(list)
67    }
68}
69
70fn build_prompt(task: &str, history: &[StepRecord]) -> Vec<ChatMessage> {
71    let mut out = vec![ChatMessage::system(format!(
72        "You are a browsing agent. Task: {task}\nReturn JSON with current_state and action[]."
73    ))];
74    for step in history.iter().rev().take(4).rev() {
75        if let Ok(j) = serde_json::to_string(&step.output) {
76            out.push(ChatMessage::assistant_text(j));
77        }
78    }
79    out.push(ChatMessage::user_text(
80        "Decide the next action(s). Return JSON {current_state, action: [...]}",
81    ));
82    out
83}
ras_agent/application/run_agent.rs

ras_agent/application/
run_agent.rs
